The reaction of `R'-overset(O)overset(||)(C)-Cl` with `R_2 CuLi` or `R_2 Cd` gives a ketone, but with `RMgX` it gives a `3^@` alcohol.
(a) Explain why `RMgX` reaction does not give ketone.
(b) Account for the difference in behaviour of `RMgX` and `R_2 CuLi` or `R_2 Cd`.
( c) What is the relationship between the reactivity of the organometallic compound and activity of the metal ?

Explanation

(a) Initially a ketone is formed.

However, as the ketone is more reactive than `R'COCl`, it reacts further with `RMgX` to give `3^@` alcohol.
(b) Since `(C - Mg)` bond is more ionic than `(C - Cu)` or `(C - Cd)` bond, `R` group of `RMgX` is more like `R^(Ӫ)` and is much more reactive towards nucleophilic addition reaction.
( c) More electropositive is the metal, more active and more ability it has to bear a positive charge and its `R` group has a more negative charge. Therefore, the nucleophlic addition reaction is faster.